Communication networks for tactical voice and data. Final report

The report summarizes the results of the project "Communication networks for tactical voice and data". When different types of services are supported in the same network, we need solutions that can simultaneously handle different types of traffic with conflicting demands. Voice group calls and distribution of position and status information are examples of important tactical communications services with different requirements for the communication resources. An important tactical requirement of modern mobile communications is that the mobile nodes should be able to communicate even in areas without coverage from radio masts or base stations. Mobile ad hoc networks are wireless multihop networks with the ability to dynamically adapt to varying conditions. A great tactical benefit of ad hoc networks is that they can be used independent of fixed infrastructure if required, which is not the case with many commercial systems for mobile communications. Mobile ad hoc networks have, however, for fundamental physical reasons usually a lower capacity than networks with base stations. Some of the important results in the report are as follows. We have developed a priority model with relative priorities, where the priority of a service depends besides its importance also on its resource cost for the network. This is particularly interesting in networks where link capacities vary greatly. We show that for network protocols with dynamic adaptation, the requirement on the adaptation delay will be unrealistic high in order to support low-latency services. To support such services, we have evaluated a new alternative resource allocation technique that is proposed in the literature. This technique is robust against topology changes and can thus handle delay-sensitive traffic in mobile situations. We show with different system examples that voice groups are possible to realize over multiple hops in both narrowband and wideband systems, provided that unnecessary overhead is minimized.